Variable capacity rotary pump



Jan. 25, N49. P. M. mAz 2,460,251

VARIABLE CAPACITY ROTARY PUMP 2 Sheets-Sheet 1 Original Filed Jan'. 13, 1944 Pascua/ fl D/a'z,

Patented Jan. 25, 1949 2,460,251 VARIABLE CAPACITY ROTARY PUMP Pascual M. Diaz, San Antonio, Tex.; Mary Louise Diaz administratrix of said Pascual M. Diaz,

deceased Original application January 13, 1944, Serial No. 518,139. Divided and this application July 31, 1944, Serial No. 547,341

. 2 Claims. 1

The present invention relates to new and useful improvements in rotary fluid pumps and is a division of my copending application Serial No. 518,139, flled in the United States Patent O'flice on January 13, 1944, now Patent No. 2,425,089.

In my aforementioned copending application there is illustrated and described a fluid drive or transmission for motor vehicles comprising a fluid driven unit for each wheel of the vehicle, a fluid driving unit or pump for said driven units, said driving unit being actuated by a prime mover on the vehicle with a transmission interposed therebetween, etc.

The primary object of the present invention is to provide a rotary pump or driving unit for a fluid drive or transmission of the aforementioned character, which rotary pump or unit includes a unique construction and arrangement for controlling the circulation of the fluid to the driven units, whereby the wheels of the vehicle may be driven at any suitable speed within a given range and braked as desired.

Another very important object of the invention is to provide a rotary fluid pump of the character described comprising novel control means whereby the pairs of wheels on opposite sides of the vehicle.

may be driven in unison or independently of each other.

Still another very important object of the invention is to provide a rotary fluid pump of the character set forth which will permit the prime mover and the vehicle wheels to be readily disconnected, whereby either may run independently of the other.

Other objects of the invention are to provide a rotary fluid pump which will be comparatively simple in construction, strong, durable, highly efiicient and reliable in operation, compact, light in weight and which may be manufactured at lowcost.

All of the foregoing and still further objects and advantages of the invention will become apparent from a study of the following specification, taken in connection with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views, and wherein:

Figure 1 is a view in side elevation with portions in section of a pump constructed in accordance with the present invention.

Figure 2 is a view partially in top plan and partially in horizontal section of the device.

Figure 3 is a bottom plan view of the gate operating means.

Figure 4 is a view in vertical section through the pump.

Referring now to the drawings in detail, it will be seen that the embodiment of the present invention which has been illustrated comprises a fluid drive unit which is designated generally by reference character 5. This fluid drive or pump unit includes a housing 30 which is formed to provide a rotor chamber 3| and diametrically opposite fluid chests 32 which are in direct communication with said rotor chamber. The fluid chests 32 have connected thereto inlet and outlet pipes 33 and 34, respectively. Seats 35 are arranged between the inlet pipes 33 and the chests 32 to be engaged by valve elements 36 forming part of gates 31 slidably mounted in said chests 32 and each including a rod 38 extending exteriorly of the chests through a packing gland 39. By referring to Figure 2 of the drawings it will be seen that the chests 32 are positioned in opposed relation to each other and that the valves 36 are arcuate for wiping contact with the periphery of a rotor 40 which is operable in the chamber 3|. The rotor 40 is fixed on a vertical shaft 4| which is rotatably mounted in the housing 30 and which extends downwardly therefrom through a bearing 10 which depends from said housing. The bearing 10 connects a variable speed and reversible transmission 6 to the pump unit 5. The transmission 6 is operatively connected in any suitable manner to the prime mover of the vehicle.

The rotor 40 has formed therein a plurality of radial slots 42 in which blades 43 are mounted for reciprocation, said blades having mounted thereon rollers 44 which are operable in cam grooves 45 which are provided therefor in the housing 30 to move said blades inwardly and outwardly in the rotor. Thus, the blades 43 are caused to have wiping contact with the periphery of the housing 30 and said blades are moved inwardly or retracted as they approach the valves 36 to clear and pass said valves. The blades 43 are provided with passages 46 extending from end to end thereof for the passage of fluid to permit said blades to reciprocate freely.

The gates 37 are slidably mounted to permit the valves 36 to be moved toward and away from the periphery of the rotor 40, and when positioned in wiping contact with said rotor, bring about operation of the pump unit 5 to actuate driven units 8, one of which is operatively connected in any suitable manner to each wheel of the vehicle. However, as the gates 3'! are moved away from the rotor, the fluid is permitted to pass between said gates and said rotor, thereby reducing the pressure and circulation to the units 8. When the valves 36 are positioned approximately midway between the periphery of the rotor 40 and the seats 35 substantially the full volume of fluid may bypass the gates 31 and circulation to the units 8 ceases.

When the gates 31 are fully opened, the valves 36 are engaged on the seats 35 and communication between the unit 5 and the units 8 is positively closed. In this manner a full braking 3 action on the wheels of the vehicle is brought about. Howeve i it will be seen that as the valves 36 approach the seats 35 the fluid circulation between the unit 5 and the units 8 will be gradually reduced for causing the gradual application of the braking action on the vehicle wheels.

Substantially L-shaped arms 49 are slidably mounted in guides 50 which are provided therefor and are detachably and adjustably connected at one end to the outer end portions of the rods 38. Coil springs 5| are connected to the arms 49 for yieldingly urging the gates 31 toward closed position in the direction of the rotor 40.

The inlet pipes 33 of the unit 5 are connected to the outlets 32 of the units 8 and the outlet pipes 34 of said unit 5 are connected to the inlets 2| of said units 8. The inlet and outlet pipes 33 and 34, respectively, of the unit 5 are so arranged as to connect one of the chests 32 to a pair of the units 8 which drive the Wheels on one side of the vehicle, while the other pair of units 3, which drive the wheels on the other side of the vehicle, are connected to the other chests 32.

Thus, all of the units 8 may be driven in unison or either pair of said units 8 may be actuated while the other is idle. This is accomplished through the alternate operation of the gates 31 relative to the rotor 40, it being understood that when both gates 31 are positioned to have wiping contact with said rotor, the driven units 8 will be simultaneously driven by the unit 5. Adjustment of one of the gates 31 away from the rotor 40 to a substantially intermediate position will cut out the drive to one pair of the units 8 while the other units 8 are being actuated by the unit 5.

An operating means 54 is mounted beneath the housing of the unit 5 for operating the gates 31 in the manner hereinbefore described. This operating means 54 includes a pair of bell crank levers 55 pivotally secured, at 56, beneath the housing 30. The bell crank levers 55 comprise comparatively short and long arms 51 and 58, respectively, together with converging extensions 53 which are formed integrally with the angles of said bell crank levers. The extensions 59 are engageable by a head 60 on one end portion of a reciprocating rod 6| forming a part of a dash pot which is designated generally by reference character 62. The arms 58 of the bell crank levers 55 are engageable with rollers 63 which are mounted on the arms 49. Operating rods 64 are connected at one end to the short arms 51 of the bell crank levers 55 by pin and slot connections 3|. The rods 64 are operable independently of each other to permit adjustment of either of the gates 31.

Operation of the gates 31 in unison may be had by longitudinal sliding movement of the rod 6| of the dash pot 62. Any suitable means, such as a foot pedal, may be provided for actuating the rod 6|. The dash pot 62 slows the movement of the gates 31 toward open position and of the valves 36 toward the seats 35, whereby a gradual braking action on the wheels may be brought about. The construction and arrangement of the dash pct 62 is such that initial movement of the rod 6| will be comparativelyrapid to move the gates 31 away from the rotor until the valves 36 are approximately midway between said rotor and their seats 35. This is the idling position and upon further operation of the gates 31 to bring about movement of the valves 36 tow'ards 4 their seats 35, the dash pct 62 functions to prevent quick closing of said valves and too sudden application of the braking action on the vehicle wheels as a result.

Referring to Figure 3, of the drawing, it will be observed that the dash pct '62 comprises a cylinder 90 which is closed at one end and said one end slidably supports the rod 6|. A piston 65 is The inner ends of the springs 5| are connected to the bearr the foregoing.

fixed on the rod GI and moves into and out of the cylinder 30 by the operation of the aforementioned brake pedal or other operating means for said rod 6|. Upon initial movement of the rod 6| toward the unit 5 the piston 65, which is outside of the cylinder 90, enters said cylinder through the open end thereof as the gates 31 move into idling position with the valves 36 approximately midway between the rotor 40 and the seats 35. The piston 65 upon entering the cylinder is checked through the medium of a suitable valve arrangement 66 constituting a portion of the dash pct 62, whereby the movement of said gates and the valves 36 will be more gradual for gradually applying the braking action to the vehicle wheels. The valve 66, in the embodiment shown, is a quick-acting check valve which admits air freely to the cylinder 3|! as the piston 65 moves outwardly therein but which traps the air in the cylinder when said piston 35 moves inwardly for retarding said piston. The pin and slot connections 8| permit operation of the bell crank levers 54 by the rod 6| without affecting the rods 64.

It is thought that the operation of the device will be readily apparent from a consideration of Briefly, the transmission 6 is driven from the prime mover of the vehicle. The unit 5 is driven from the transmission 6 through the shaft 4|. With the gates 31 closed and the valves 36 in open position and engaged with the periphery of the rotor 40, the fluid in the system circulates under pressure through the units 3 and the unit 5 for actuating the wheels of the vehicle. As the gates 31 are opened or, in other words, moved away from the rotor 40, circulation of the fluid through the system is decreased and the speed of the driven units 8 is reduced. As hereinbefore set forth, by opening one of the gates 31 and permitting the other to remain closed, the pairs of units 8 on either side of the vehicle may be rendered inoperative while the other pair of said units continues to be driven.

It is believed that the many advantages of a rotary fluid pump constructed in accordance with the present invention will be readily understood and although a preferred embodiment of the device is as illustrated and described, it is to be understood that changes in the details of construction and in the combination and arrangement of parts may be resorted to which will fall within the scope of the invention as claimed.

What I claim is:

1. In a fluid drive unit, a housing, a rotor chamher, a plurality of fluid chests in communication with the chamber, an inlet and outlet port for each chest, a power shaft centrally Journaled in the housing, a rotor secured to the shaft. a plurality of radially slidable blades on the shaft for engaging with the walls ofthe chamber, a gate in each che'st slidable between the inlet and outlet ports for engagement with the rotor, a plurality 'of rollers carried by the blades, the housing having a plurality of cam grooves to receive the rollers whereby to impart radially sliding movement to the blades during rotation of the rotor for clearing the gates, a plurality of arms slidably mounted on the housing and connected to the gates, rollers carried by the arms, a plurality of hell crank levers pivotaliy mounted on the housing and engaging the arm rollers, means for moving the crank levers to simultaneously operate the gates, and a dashpot connected to the last-claimed means for operating the gates gradually,

2. In a mechanical movement, a pair of aligned reciprocable operating arms, a pair of bell crank levers having fixed pivots aligned parallel to the axis of the operating arms, each lever comprising a short arm and along arm, an extension'on each lever, the long arm of each lever being in engagement with its respective operating arm, a rod slidably attached to the short arm of each lever to operate the said lever independently, a single 6 means engageable with the lever extensions to operate both levers simultaneously, and means for actuatingthe last-claimed means to control the rate of travel of the operating arms.

. PASCUAL M. DIAZ.

REFERENCES CITED The following references are of record in the file of this patent:

v UNITED STATES PATENTS Number 

